> -----Original Message-----
> From: Li, Xiaoyun
> Sent: Monday, October 2, 2017 5:13 PM
> To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Richardson, Bruce
> <bruce.richard...@intel.com>
> Cc: Lu, Wenzhuo <wenzhuo...@intel.com>; Zhang, Helin <helin.zh...@intel.com>;
> dev@dpdk.org; Li, Xiaoyun <xiaoyun...@intel.com>
> Subject: [PATCH v4 3/3] efd: run-time dispatch over x86 EFD functions
>
> This patch dynamically selects x86 EFD functions at run-time.
> This patch uses function pointer and binds it to the relative
> function based on CPU flags at constructor time.
>
> Signed-off-by: Xiaoyun Li <xiaoyun...@intel.com>
> ---
> lib/librte_efd/rte_efd_x86.h | 41 ++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 38 insertions(+), 3 deletions(-)
>
> diff --git a/lib/librte_efd/rte_efd_x86.h b/lib/librte_efd/rte_efd_x86.h
> index 34f37d7..93b6743 100644
> --- a/lib/librte_efd/rte_efd_x86.h
> +++ b/lib/librte_efd/rte_efd_x86.h
> @@ -43,12 +43,29 @@
> #define EFD_LOAD_SI128(val) _mm_lddqu_si128(val)
> #endif
>
> +typedef efd_value_t
> +(*efd_lookup_internal_avx2_t)(const efd_hashfunc_t *group_hash_idx,
> + const efd_lookuptbl_t *group_lookup_table,
> + const uint32_t hash_val_a, const uint32_t hash_val_b);
> +
> +static efd_lookup_internal_avx2_t efd_lookup_internal_avx2_ptr;
> +
> static inline efd_value_t
> efd_lookup_internal_avx2(const efd_hashfunc_t *group_hash_idx,
> const efd_lookuptbl_t *group_lookup_table,
> const uint32_t hash_val_a, const uint32_t hash_val_b)
> {
> -#ifdef RTE_MACHINE_CPUFLAG_AVX2
> + return (*efd_lookup_internal_avx2_ptr)(group_hash_idx,
> + group_lookup_table,
> + hash_val_a, hash_val_b);
I don't think you need all that.
All you need - build proper avx2 function even if current HW doesn't support it.
The existing runtime selection here seems ok already.
Konstantin
> +}
> +
> +#ifdef CC_SUPPORT_AVX2
> +static inline efd_value_t
> +efd_lookup_internal_avx2_AVX2(const efd_hashfunc_t *group_hash_idx,
> + const efd_lookuptbl_t *group_lookup_table,
> + const uint32_t hash_val_a, const uint32_t hash_val_b)
> +{
> efd_value_t value = 0;
> uint32_t i = 0;
> __m256i vhash_val_a = _mm256_set1_epi32(hash_val_a);
> @@ -74,13 +91,31 @@ efd_lookup_internal_avx2(const efd_hashfunc_t
> *group_hash_idx,
> }
>
> return value;
> -#else
> +}
> +#endif
> +
> +static inline efd_value_t
> +efd_lookup_internal_avx2_DEFAULT(const efd_hashfunc_t *group_hash_idx,
> + const efd_lookuptbl_t *group_lookup_table,
> + const uint32_t hash_val_a, const uint32_t hash_val_b)
> +{
> RTE_SET_USED(group_hash_idx);
> RTE_SET_USED(group_lookup_table);
> RTE_SET_USED(hash_val_a);
> RTE_SET_USED(hash_val_b);
> /* Return dummy value, only to avoid compilation breakage */
> return 0;
> -#endif
> +}
>
> +static void __attribute__((constructor))
> +rte_efd_x86_init(void)
> +{
> +#ifdef CC_SUPPORT_AVX2
> + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2))
> + efd_lookup_internal_avx2_ptr = efd_lookup_internal_avx2_AVX2;
> + else
> + efd_lookup_internal_avx2_ptr = efd_lookup_internal_avx2_DEFAULT;
> +#else
> + efd_lookup_internal_avx2_ptr = efd_lookup_internal_avx2_DEFAULT;
> +#endif
> }
> --
> 2.7.4
